High Operating Time Additional Heater - Danfoss Heat Pump Troubleshooting Manual

Troubleshooting Guide
Only runs on the additional heat
Action:
Ensure that the heat pump is not in additional heater only mode. If additional heater only mode is selected change to auto, the heat
pump then regulates both the compressor and the additional heater.
The compressor cannot run due to an alarm
Action:
Check the alarm that is indicated in the display.
See chapter Alarm in the installation instructions or the fault tracing guide.
Rectify the problem.
The integral value has reached the start level for the auxiliary heater
Action:
Check what integral value is set in the control computer.
If the auxiliary heater is in operation because the integral value has counted down to the start value, the computer reacts as it should,
see the Installation instructions for further information.
Peak heat operation (anti-legionella function) is running
Action:
Check the heat pump settings for peak heat. See the instructions for the relevant model. Peak heat operation occurs in connection with
hot water production with the set interval.
Room
Action:
Reduce the Room set-point value. 1 degree increase in room set point value affects the curve incline by 3 degrees. The heat pump has
been adjusted for a room temperature of 20 degrees and curve 40 set. If the room value has increased to ROOM 23 it means that there
has been an increase in the curve of 9 degrees, that is corresponds to CURVE 49 and the addition will interrupt earlier.
Curve min
Action:
Check the curve min, because it is the lowest supply temperature. If it is set at 30 degrees it is 30 degrees that the compressor works to
if the heat pump is in heat stop.
Incorrect flow over hot side of the heat pump
Action:
Adjust the system to obtain the correct delta t. Check the difference between the heat pump supply and return line using a digital
thermometer. The difference should be about 7-10°C (can vary depending on refrigerant). A lower delta-t results in reduced efficiency
in the heat pump
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High operating time additional heater

VMIFB202